Airbag control unit with part number 985105677R

What does the airbag control unit 985105677R do?

The airbag control unit 985105677R is the central control unit of the restraint system (SRS) of Renault. It evaluates the signals from the crash sensors, decides in an emergency within fractions of a second which airbags and seatbelt pretensioners to trigger, and monitors the system continuously.

The unit reports faults in the system via the airbag warning light in the instrument cluster. To do this, it constantly checks the sensors, the wiring and the trigger circuits needed for an airbag deployment.

After an accident the unit stores crash data and locks itself. Only the repair lifts this lock.

Why does the control unit 985105677R fail?

The most common cause is crash data stored after an accident, even if no airbag has deployed; a normal diagnostic tool cannot clear it. Other causes are aged electronic components, cold solder joints, moisture and corrosion at plug connectors, and voltage spikes, for example from a weak battery or an improper jump start.

Crash data is created as soon as the unit registers an accident, regardless of whether an airbag finally fired. It remains in the memory even when the vehicle has long since been driven again, which is why the fault cannot be removed this way.

The remaining causes lie in the electronics themselves. Over the years, components on the circuit board age, solder joints can go cold, and moisture or corrosion at plug connectors disturbs signal transmission. Voltage spikes additionally stress the electronics and can trigger faults.

How can you tell that the 985105677R is defective?

A defect shows as an airbag warning light in the instrument cluster that is lit permanently or intermittently, as an error message there, as a diagnostic tool without connection to the control unit, and as a fault memory that cannot be cleared.

• The airbag warning light in the instrument cluster is lit permanently or intermittently.
• The instrument cluster shows an error message about the airbag system.
• The diagnostic tool does not connect to the control unit.
• The fault memory cannot be cleared.

If any of these signs is present, airbags and seatbelt pretensioners may not be able to trigger in an emergency. In that case, do not simply carry on driving, but have the cause clarified.

Which vehicles is the 985105677R fitted in?

The control unit 985105677R is fitted in these vehicles: Renault Koleos II (from 2016).

The vehicles for which this control unit is listed are shown here:

• Renault Koleos II (from 2016)

Compare the part number on the label of the removed unit with this page. That way you can be sure you have the right unit in front of you. Whether the control unit is actually defective is only shown by the fault memory, which you should have read out beforehand. Only this log clarifies whether the control unit is the cause or whether a plug or a cable is behind the fault.

For the same vehicles, we also repair control units with the part numbers 985105619R, 985106952R.

How does the repair of the 985105677R work?

First have the fault memory read out and enclose the log. Then disconnect the battery and only afterwards remove the control unit. Next, create a repair order online and send the unit in well packed.

At Airbag24 the team tests the unit on the test bench, replaces defective components, deletes stored crash data and carries out a function test. Processing at Airbag24 usually takes 3–4 working days. Afterwards your own unit is returned to you.

Our repairs come with 2 years' statutory liability for defects.

The repaired control unit comes back with all vehicle data and is ready for use as soon as it is refitted — no coding or programming is required.

How does the control unit 985105677R get to Airbag24?

You send the unit in as a parcel or book a UPS collection for an extra charge. After the repair, Airbag24 returns it to you by UPS. Put the printed repair order into the parcel and pack the unit shockproof.

A stable packaging protects the control unit on its way, both during dispatch and during collection by UPS.